1. Field of the Invention
The present invention relates to a copying machine provided with a sheet stapling device.
2. Description of the Prior Art
The Xerox Disclosure Journal Vol. 8, No. 4, of July/August 1983, pages 309-311, describes a copying machine with a sheet stapling device. In this machine, the images are applied to the copy sheets in such an orientation that the copies arrive in a collecting tray with the side to be stapled facing away from the operating side of the machine. To staple the copy sheets collected in the tray in the upper left-hand corner relative to the image, the stapling means is necessarily arranged in the hindmost part of the copying machine facing away from the operating side of the copying machine.
Rising above the rest of this copying machine is a cap which covers the hindmost part of the collecting tray. An elongated rectangular slot is formed in the front wall of this cap permitting a bundle of sheets to be inserted manually under the stapling means. During insertion, the bundle slides in an inclined downward direction on the hindmost part of the horizontal plate of the collecting tray. In the stapling position, the bundle will be bent because it is held by hand and the parts of the sheets situated under the stapling means will be shifted imbricately. If a bundle inserted into the slot is relatively thick, this shifting will be relatively large. This will cause the sheets to be stapled at a place where they have been shifted imbricately forming a bundle of incorrectly fastened sheets.
The latter drawback of this copying machine might be met somewhat by enlarging the distance between the slot and the stapling means permitting the bundle to be inserted less obliquely into the slotted opening. However, the bundle in the Xerox machine is to be passed practically wholly through the slot and, consequently, its proper holding would no longer be possible if the distance was increased. Moreover, increasing the distance increases the risk that in sliding on the horizontal plate the lowermost sheet of the bundle will be arrested and will not properly arrive under the stapling means.
U.S. Pat. No. 4,184,622 describes a typical stapling device used in a copying machine to staple sets of copy sheets formed in the copying machine. The copying machine described in this patent, however, is not adapted for stapling a bundle of sheets inserted manually into the machine.
None of the above-described copying machines are suitable both for stapling sets of sheets easily inserted manually in a flat condition under the stapling device and for automatically stapling sets of copy sheets formed in the copying machine.